When it comes to skeptic's opinion about religion it often consists of two differing ideas. One of them is that religion is evil, the cause of most of the world's problems and if we get rid of it the world would be a much better place. The second one is that religion is a poison. I will refer to these as the Richard Dawkins' approach and the Christopher Hitchen's approach, respectively.
I do not think that religion is inherently evil. It is true that most of our history is the result of religious conflict between different groups of people. But it is not that religion is inherently evil, however. I plan to write in the future what I think is the major source of all our conflict in the world but for now I just want to say that religion has created very strong differences between different groups of people. It were these differences that lead to the conflict and wars that most our history is soaked with blood with.
Now if you look at the 20th century you realize something interesting. All the major wars were not the result of religion whatsoever. You even had some atheistic countries which were responsible for mass genocide, such as the Soviet Union. However, the Soviet Union did not kill for religious reasons. Nor did Nazi Germany kill for religious reasons (they were Christian). Nazi Germany and Soviet Union killed for different reasons. Because the nations were able to identity themselves, not with religion, but with something else. It were these differences that developed into the conflicts, religion had nothing to do with this. Approximately 200 million people were murdered by states and wars in the 20th century, little of that had to do with religion.
Thus, if you are the supporter of the Richard Dawkins approach you need to answer this problem. How can you claim that religion is the majority cause of the problems in the world and ignore the 20th century? Richard Dawkins would have us believe that if we get rid of religion everything would be nice and peaceful. Of course, I know I just strawmaned his position, however, it is not that much off from what Dawkins is saying, his position is similar to how I described it. And it is here that I lose a lot of respect for Dawkins (I never once liked Dawkins). When Dawkins was asked about Stalin his response was that Stalin was "like a religious person". Wow, Dawkins committing the no-true Scottsman fallacy, I would expect more from him. The problem with the Dawkins' approach to religion is that it does not address the problem I set up.
The approach that I much strongly prefer is the Hitchen's approach. It does not say that religion is inherently evil. It does not say that if religion is gone the world would be so much better. It says that religion is a poison. It is not necessary for morals. It does not add nearly as much to morals as it takes away from morals. You can see this among very fundamentalist religious followers. If they are very strict with their religion they often do very immoral things. Mainly the religious people that are good people are the liberal or moderate theists.
This is the approach that I hold. Religion is simply not necessary for our morals, it is not inherently evil however, furthermore it is a poison. It makes good people do bad things in many instances. If religion is magically gone tomorrow then the world will be better, but not so much better, there would be a lot of conflict nonetheless.